CN104654573A - A solidification latent heat heat pump for recycling waste heat - Google Patents

Abstract

The utility model provides a retrieve waste heat-melting formula latent heat pump that solidifies belongs to the heat pump field, including compressor, condensate tank drying filter, throttling arrangement, evaporation water tank, vapour and liquid separator, evaporation water tank circulating pump, condensate tank circulating pump, level gauge, user's heat utilization system, water collector, dirt separator, running water solenoid valve, drainage solenoid valve and controller. Compared with a conventional sewage source heat pump system, the deep utilization of domestic sewage is realized, two processes of alternately freezing and melting ice on the surface of a heat exchange are realized through the waste heat melting and deicing of the domestic sewage, the temperature of the domestic sewage is reduced, the perennial normal starting and stable operation of a heat pump unit are ensured, and meanwhile, the heat provided by a low-level heat source is ensured to meet the heat load demand of users.

Description

A solidification latent heat heat pump for recycling waste heat

technical field

The invention belongs to the field of heat pumps, and in particular relates to a solidification latent heat heat pump which utilizes waste heat sensible heat for deicing and utilizes waste heat sensible heat and latent heat as low-level heat sources of the heat pump.

Background technique

With the rapid development of my country's economy, the level of urbanization and the continuous improvement of people's living standards, the demand for domestic hot water in families, hotels, schools, hospitals, baths, etc. is also increasing. At present, there are usually the following ways to prepare domestic hot water: (A) hot water boilers using high-grade heat sources (such as coal, oil, gas, electric heating); (B) using solar energy as the main heat source, gas boilers Or a hot water system with electric heating as an auxiliary heat source; (C) heat pump hot water systems such as water source heat pumps or air source heat pumps, etc. Since domestic hot water still has a relatively high temperature (up to 30°C or higher) when it is discharged after utilization, although hot water boilers using high-grade heat sources have the advantages of fast heating and stable system operation, from the perspective of my country's energy policy and economic From a general point of view, hot water boilers are not the best way to prepare hot water. They not only consume primary energy, but also have high operating costs. At the same time, the low-level thermal energy contained in domestic sewage is wasted because it cannot be used scientifically. Solar energy is a green renewable energy source, and it is worth advocating to use it as a heat source to provide domestic hot water. However, solar energy has the disadvantages of instability and dispersion, which limits the use of solar water heating systems. For heat pump hot water systems, surface water source heat pumps such as rivers, rivers, lakes, seawater, and urban sewage are recognized as an excellent energy-saving and environmentally friendly technology due to their high heating coefficient and low initial investment. Surface water source heat pumps have not been widely promoted. The reason is that surface water suitable for heat pump water sources is not everywhere. The space is already small and there is a danger of freezing damage or clogging the pipes.

In order to solve the problem of small sensible heat energy space of low-level heat sources, people consider making fluid ice to extract solidification latent heat to meet the needs of engineering loads. The invention patent (the application number is CN 200610009617.5) proposes a solidification latent heat heat pump that utilizes the sensible heat of low-level heat source to supply water for defrosting. It utilizes the characteristics of incompatibility between air and water and good fluidity, and uses air as the intermediary cooling fluid. In this way, "rootless ice" is produced. After the air exchanges heat directly with water, it then exchanges heat with the refrigerant in the heat pump evaporator. Therefore, the heat pump is essentially an air source heat pump. Since the temperature after direct heat exchange between air and water is about 0°C and is very close to the saturation state, the surface of the evaporator is prone to frosting during the process of extracting the latent heat of solidification heat pump. In order to improve the heating efficiency of the heat pump, The invention utilizes part of the sensible heat of low-level heat source water for defrosting. The invention makes good use of the latent heat of the low-level heat source water and effectively solves the problem of evaporator defrosting. In addition, in order to solve the problem that the air-cooled heat pump has low working efficiency or even cannot operate normally when the ambient temperature is low, the invention patent (application number is CN 200910184024.6) proposes a dual heat source heat pump, which has two operating modes, When the ambient temperature is high, the air source is used as the heat source, and when the ambient temperature is low, part of the latent heat of water is used as the heat source, thus ensuring that the heat pump system has a high working efficiency when the ambient temperature is low, but how to prepare flowing ice , to meet the demand of continuous extraction of condensation heat from water is the key to the stable operation of the heat pump system. In the process of extracting the heat of solidification, in order to make the frozen ice off the heat exchange surface in time while satisfying the economic benefits, and make the ice water flow in the pipeline without blockage, the invention patent (patent number is CN 200610009616.0, CN 200610009740.7) proposes a scraper-type solidification heat collection device, which peels off the ice frozen on the heat exchange tube from the wall in the form of mechanical "scraping", mixes with water to form ice flocs and takes them away with the water, thereby continuously collecting Solidification heat, but the method of mechanical deicing has the problems of complex equipment structure and high cost.

When domestic sewage is recycled, it has the remarkable characteristics of high waste heat temperature and rich heat energy (it can reach above 30°C), but when it is used as a low-level heat source of water source heat pump, when domestic hot water is heated by water source heat pump unit, the following problems will occur : (1) In areas where the temperature is low in winter, the temperature of tap water is low in winter, such as about 5°C, while the temperature of waste heat is about 30°C. Use a low-level heat source at about 30°C to heat the tap water at about 5°C to When the domestic water temperature requirements are met, the heat pump unit cannot start normally under this working condition. (2) When the heat pump is heating domestic hot water, the temperature of the cold water on the condensing side gradually increases, resulting in a gradual increase in the condensing temperature. At the same time, due to insufficient sewage water, domestic sewage needs to be stored in the water storage tank, and the evaporating side The temperature of the sewage gradually decreases, resulting in a gradual decrease in the evaporation temperature. During the entire operation of the heat pump unit, the condensing temperature and evaporation temperature vary widely, and the stability of the heat pump unit operation is poor. (3) When the tap water at about 5°C is heated to meet the temperature requirements of domestic water through the heat pump unit, only the sensible heat of domestic sewage is recovered, which cannot meet the heat load needs of users on the condensation side. Therefore, under the general call of the international community for energy conservation and emission reduction, how to effectively solve the above problems, so as to rationally and effectively utilize domestic waste water and other waste heat resources, and achieve continuous and stable heat demand for users is of great significance.

Contents of the invention

The technical problem to be solved by the present invention is to realize reasonable and effective utilization of domestic sewage, using part of the low-temperature sensible heat and solidification latent heat of sewage as the heat source, and at the same time using part of the sensible heat of the waste water to achieve alternate freezing and freezing on the heat exchange surface through the heat-thawing method The two processes of melting and ice are used to maintain the evaporation temperature of the heat pump unit within a relatively stable range, to ensure the normal and stable operation of the heat pump unit, and to ensure that the heat provided by the low-level heat source meets the heat load demand of the user. A solidification latent heat heat pump that recovers waste heat and melts.

Technical scheme of the present invention is as follows:

A recovery waste heat thermal melting solidification latent heat pump, including a compressor, a condensed water tank, a dry filter, a throttling device, an evaporating water tank, a gas-liquid separator, a circulating pump for the evaporating water tank, a circulating pump for the condensed water tank, a liquid level gauge, and a user heat pump. Utilization system, water collector, decontamination device, tap water solenoid valve, drain solenoid valve and controller; the exhaust port of the compressor and the refrigerant side of the condensed water tank, the dry filter, the throttling device, and the refrigerant side of the evaporating water tank pass through the pipeline in sequence connection, the suction port of the compressor is connected to the outlet of the gas-liquid separator through a pipeline; the tap water solenoid valve is connected to the condensate tank through a tap water supply pipe, and the inlet of the tap water supply pipe is higher than the top of the liquid level gauge; the drain solenoid valve is connected to the evaporator through a drain pipe The water tank is connected; the user's heat utilization system is connected to the condensed water tank through pipelines; the water collector, decontamination device and the evaporation water tank are connected in sequence through pipelines; the suction port and outlet of the circulation pump of the evaporation water tank are connected to the evaporation water tank through pipelines, The suction and outlet of the condensate tank circulation pump are connected to the condensate tank through pipelines; the liquid level gauge is installed on the outer wall of the condensate tank, and its bottom is higher than the water outlet connected to the user's heat utilization system.

The operation mode of the present invention is: the controller reads the indicated value of the liquid level gauge and compares it with the minimum liquid level setting value of the condensed water tank. When the indicated value is lower than the minimum liquid level set value, the tap water solenoid valve opens to fill the condensed water tank. water, when the indicated value reaches the maximum liquid level setting value of the condensed water tank, the tap water solenoid valve is closed, the circulating pump of the evaporating water tank and the circulating pump of the condensed water tank are started, and then the heat pump unit is started. When the water temperature in the condensed water tank reaches the temperature required by the user, the heat pump The unit stops running, and then the circulating pump of the evaporating water tank and the circulating pump of the condensed water tank stop running; the user takes high-temperature hot water from the condensed water tank, collects the waste water through the water collector after use, and physically decontaminates the waste water through the decontamination device , the waste water flows into the evaporating water tank for storage, and melts the solid ice outside the refrigerant heat exchange tube of the evaporating water tank. When the set value is on line, the drain solenoid valve is closed; when the water storage level in the evaporation water tank is higher than the overflow port, the excess waste water is discharged from the overflow.

Compared with the conventional sewage source heat pump system, the present invention not only realizes the heat recovery and utilization of domestic sewage, but also realizes the two processes of alternating freezing and melting ice on the heat exchange surface through the waste heat melting and deicing of domestic sewage, which reduces the life cost. The temperature of the sewage ensures the normal start-up and stable operation of the heat pump unit all year round. The device realizes the utilization of waste water coagulation heat, ensures that the heat provided by the low-level heat source meets the heat load demand of the user, and improves the heating efficiency of the heat pump, and the invention has a simple structure and is easy to maintain and repair, and can be widely used in domestic hot water supply and heating area.

Description of drawings

Accompanying drawing 1 is a structural representation of the present invention.

In the figure: 1 compressor, 2 condensed water tank, 3 dry filter, 4 throttling device, 5 evaporating water tank, 6 gas-liquid separator, 7 evaporating water tank circulating pump, 8 condensed water tank circulating pump, 9 liquid level gauge, 10 user Heat utilization system, 11 water collector, 12 decontamination device, 13 tap water solenoid valve, 14 drain solenoid valve, 15 controller.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with technical solutions and accompanying drawings.

When realizing the present invention, compressor 1, condensation water tank 2, drier filter 3, throttling device 4, evaporation water tank 5, gas-liquid separator 6 are connected successively, and its working principle is basically the same as general water source heat pump; Tap water solenoid valve 13 Connected with the condensed water tank 2 through the tap water supply pipeline; the drain solenoid valve is connected with the evaporated water tank 5 through the drain pipe 14; the user heat utilization system 10 is connected with the condensed water tank 2 through the pipeline; The evaporation water tank 5 is connected sequentially through pipelines; the suction inlet and outlet of the evaporation water tank circulation pump 7 are connected with the evaporation water tank 5 through pipelines, and the suction inlet and outlet of the condensation water tank circulation pump 8 are connected with the condensation water tank 2 through pipelines; 9 is installed on the outer wall of the condensed water tank 2, and its bottom position is higher than the water outlet connected to the user's heat utilization system 10. The heat exchange tube in the evaporating water tank 5 can be a smooth copper tube or a finned tube; the condensed water tank 2 can be a direct system as shown in accompanying drawing 1, and the inlet position of the tap water pipe of the condensed water tank 2 is higher than that of the liquid level gauge 9 tops. At the same time, the condensed water tank 2 can also be replaced by a condenser to form an indirect system.

The operating mode of the present invention is: the controller 15 reads the indicated value of the condensed water tank 2 liquid level gauge 9 and compares it with the set value of the minimum liquid level of the condensed water tank 2. When the indicated value is lower than the set value of the minimum liquid level, the tap water electromagnetic The valve 13 is opened to fill the condensed water tank 2 with water. When the indicated value reaches the maximum liquid level setting value of the condensed water tank 2, the tap water solenoid valve 13 is closed, the circulating pump 8 of the evaporating water tank and the circulating pump 9 of the condensed water tank are started, and then the heat pump unit is started. When the water temperature in the condensed water tank 2 reaches the temperature required by the user, the heat pump unit stops running, and then the circulating pump 8 of the evaporating water tank and the circulating pump 7 of the condensed water tank stop running; The water tank 11 collects the waste water. After the waste water is physically decontaminated by the decontamination device 12, the waste water flows into the evaporating water tank for storage, and melts the solid ice outside the refrigerant heat exchange tube of the evaporating water tank 5. When the water temperature is low When the discharge temperature is lower than the set value, the drain solenoid valve 14 is opened to drain water, and when the water temperature is high and the water discharge temperature is above the set value, the drain solenoid valve 14 is closed; when the water storage level in the evaporation water tank 5 is higher than the overflow port , excess waste water is discharged from the overflow.

Claims (10)

1. A recovery waste heat thermal melting solidification latent heat pump, including a compressor (1), a condensation water tank (2), a dry filter (3), a throttling device (4), an evaporation water tank (5), and a gas-liquid separator (6), evaporating water tank circulating pump (7), condensed water tank circulating pump (8), liquid level gauge (9), user heat utilization system (10), water collector (11), decontamination device (12), tap water Solenoid valve (13), drain solenoid valve (14) and controller (15); it is characterized in that compressor (1) exhaust port and condensed water tank (2) refrigerant side, dry filter (3), throttling device (4), the refrigerant side of the evaporating water tank (5), and the gas-liquid separator (6) are connected in sequence through pipelines to form a heat pump working medium circulation loop; the ice storage side of the evaporating water tank (5) is an open system, and the user's heat utilization system (10) The waste water after utilization is collected by the water collector (11) and decontaminated by the decontamination device (12) and enters the evaporation water tank (5). ) after the sensible heat of waste water melts ice, its ice-water mixture is discharged through the drain solenoid valve (14); the liquid level gauge (9) is installed on the outer wall of the condensed water tank (2), and its bottom position is higher than that of the user's heat utilization system (10 ) connected outlet. 2. A recovery waste heat heat melting solidification latent heat heat pump according to claim 1, characterized in that the condensation side is a direct open system, and the inlet position of the tap water pipe of the condensation water tank (2) is higher than that of the liquid level gauge (9). top. 3. A recovery waste heat heat melting solidification latent heat heat pump according to claim 1, characterized in that the condensed water tank (2) is replaced by a condenser, and the condenser is a plate heat exchanger or a shell and tube heat exchanger. 4. A recovery waste heat heat melting solidification latent heat heat pump according to claim 1 or 2, characterized in that the heat exchange tubes in the condensation water tank (2) are bare tubes or finned tubes. 5. A recovery waste heat heat melting solidification latent heat heat pump according to claim 1, 2 or 3, characterized in that the heat exchange tubes in the evaporation water tank (5) are bare tubes or finned tubes. 6. A recovery waste heat heat melting solidification latent heat heat pump according to claim 4, characterized in that the heat exchange tubes in the evaporation water tank (5) are bare tubes or finned tubes. 7. According to claim 1, 2 or 6, a recovery waste heat heat melting solidification latent heat pump is characterized in that the stirring system of the evaporation water tank (5) is an external evaporation water tank circulating pump or a built-in stirrer; the condensation water tank ( 2) The stirring system is an external condensate tank circulation pump or a built-in agitator. 8. A recovery waste heat thermal melting solidification latent heat heat pump according to claim 3, characterized in that the stirring system of the evaporation water tank (5) is an external evaporation water tank circulation pump or a built-in stirrer. 9. A kind of recovery waste heat heat melting solidification latent heat heat pump according to claim 4, characterized in that the stirring system of the evaporation water tank (5) is an external evaporation water tank circulation pump or a built-in stirrer; the stirring of the condensate water tank (2) The system is an external condensate tank circulation pump or a built-in agitator. 10. A recovery of waste heat heat melting solidification latent heat heat pump according to claim 5, characterized in that the stirring system of the evaporation water tank (5) is an external evaporation water tank circulation pump or a built-in stirrer; the stirring of the condensate water tank (2) The system is an external condensate tank circulation pump or a built-in agitator.